# Chapter 2 | The Noun

The nouns can be divided into five declensions, according to genitive case form, as is seen in table 2E.

1. The Nominative and the Accusative

   Both of these cases have the same form now, in the singular and in the plural, and they are both counted under the title Nominative in the declensions of nouns.

2. The Dative

   The form of the dative is also the same as the nominative, singular and plural (but see 2.3.3), and that case is also counted under the title Nominative.

3. The Genitive

   The form of the genitive in the different declensions is given in the tables in this chapter and in the description of the particular declensions.

4. The Vocative

   In the vocative case, the vocative particle a is put before the noun and the initial consonant of the following noun is lenited. The form of the vocative is the same as the nominative except in the first declension and does not need to be specified separately outside of that declension (see 2.2.3 and 2.2.4(c)).

The plurals of nouns can be divided into two main classes: strong plurals and weak plurals. The two classes are described as follows:

1. Strong Plurals

   The plural of a noun is a strong plural if the noun’s plural form is the same in all the cases.

   Table 2AExamples of Strong Plurals

   The Declensions	Singular		Plural
   	Nominative	Genitive	Nominative	Genitive
   The First Declension	cás	cáis	cásanna	cásanna
   	ceol	ceoil	ceolta	ceolta
   The Second Declension	foirm	foirme	foirmeacha	foirmeacha
   	sliabh	sléibhe	sléibhte	sléibhte
   The Third Declension	feirmeoir	feirmeora	feirmeoirí	feirmeoirí
   	foráil	forála	forálacha	forálacha
   The Fourth Declension	amhránaí	amhránaí	amhránaithe	amhránaithe
   	gloine	gloine	gloiní	gloiní
   The Fifth Declension	deartháir	dearthár	deartháireacha	deartháireacha
   	lasair	lasrach	lasracha	lasracha
   Irregular Nouns	leaba	leapa	leapacha	leapacha
   	teach	tí	tithe	tithe

2. Weak Plurals

   The plural of a noun is a weak plural if the noun’s plural form is not the same in the genitive plural as the noun’s plural form in the other cases. This class includes:

   1. Nouns that end on a broad consonant and the ending consonant becomes slender in the nominative plural and the genitive singular, e.g., fear, tá na fir ag teacht, hata an fhir; eitleán, feictear na heitleáin sa spéir, athraíodh roth an eitleáin. Those nouns are only in the First Declension. An example is in the table below:

      Table 2BThe First Declension — Weak Plural

      The First Declension
      	Nominative	Genitive
      Singular	fear	fir
      Plural	fir	fear

   2. Nouns that take an a in the nominative plural with neither syncope nor an exchange of vowel or vowels nor broadening in the nominative singular — lose the ending vowel -a in the genitive plural. Those plurals are mostly in the Second Declension, e.g., géag crainn, do ghéaga a shíneadh, laige na ngéag. This is shown in the table below:

      Table 2CThe Second Declension — Weak Plural

      The Second Declension
      	Nominative	Genitive
      Singular	fuinneog	fuinneoige
      Plural	fuinneoga	fuinneog

      Note that several nouns follow the same pattern as in the First Declension, e.g., úll, itheadh na húlla, blas na n‑úll; in the Third Declension, e.g., tréad caorach, tréada is comhaltas, seoladh na dtréad; and in the Fourth Declension, e.g., gach aon neach, na neacha daonna, teacht na neach neamhshaolta.

   3. A few nouns in the Second Declension, e.g., súil, leath na súile uirthi, radharc na súl; a few in the Third Declension, e.g., mionn, na mionnaí marbha, dar bhrí na mionn; a few in the Fourth Declension, e.g., bó, tá na ba sa gharraí, cró na mbó; a few in the Fifth Declension, e.g., caora, tá na caoirigh ann, líon na gcaorach; and an occasional irregular noun, e.g., bean, tá na mná ag teacht, hataí na mban; have a separate form in the genitive plural. Examples are shown in the table below:

      Table 2DOther Weak Plurals — Examples

      The Declensions	Singular		Plural
      	Nominative	Genitive	Nominative	Genitive
      The Second Declension	ealaín	ealaíne	ealaíona	ealaíon
      	súil	súile	súile	súl
      The Third Declension	mionn	mionna	mionnaí	mionn
      The Fourth Declension	bó	bó	ba	bó
      	grásta	grásta	grásta	grást
      The Fifth Declension	caora	caorach	caoirigh	caorach
      	lacha	lachan	lachain	lachan
      Irregular Nouns	bean	mná	mná	ban
      	olann	olla	olanna	olann

When a broad consonant is made slender, this is palatalization. An -i- is placed before the end consonant to indicate a palatalization, e.g., cnoc, cnoic. The palatalization is done in the same way if the end-consonant has an ae in front, e.g., aer, aeir.

It is customary to change certain vowels when the following consonant is narrowed:

1. -ea- and -io- to -i-, e.g., ceann, cinn; fionn, finn (but in certain monosyllabic nouns ea- to ei-, e.g., each, eich);
2. -éa- and -ia- to éi-, e.g., béal, béil; iasc, éisc;
3. -ío- to -í-, e.g., síol, síl;
4. in the polysyllabic nouns, -ach to -aigh, -each to -igh, -íoch to -ígh, e.g., bithiúnach, bithiúnaigh; cléireach, cléirigh; gaiscíoch, gaiscígh. That change applies to these monosyllabic nouns which were once written as disyllabic nouns, e.g., dúch, dúigh; fiach, fiaigh; and occasionally with other monosyllabic nouns, e.g., fraoch, fraoigh.

When a slender consonant is made broad, this is broadening. The -i- directly in front of the consonant is dropped to broaden the noun, e.g., athair, athar; droim, droma.

It is customary to change certain vowels as follows when they are broadened:

1. -ei- and -i- to -ea-, e.g., greim, greama; mil, meala;
2. -éi- to -éa-, e.g., úinéir, úinéara;
3. -oi- and -ui- to -o-, e.g., fuil, fola; toil, tola.

When a short, unaccented vowel or vowels are dropped from the word when it is inflected, this is syncopation, e.g., cathair, cathrach; obair, oibre.

A compound word is made by connecting two words or more together, e.g, bunscoil; príomhoifigeach; ríomheolaíocht. The second word in a compound word is lenited, e.g., deargbhuile; rósghairdín, except when d, n, t, l or s come with it, e.g., antráth; catsúil. The hyphen is used in a compound:

1. between two vowels, e.g., fo-aicme; mí-ádh; mí-iompar; ró-olc;
2. between common consonants, e.g., droch-chaint; gearr-rás; gnáth-thuarastal;
3. between two prefixes, e.g., comh-cheolfhoireann; mór-cheoldráma; sin-seanathair;
4. in contexts when the compound would be unrecognizable without the hyphen, for example, between the prefixes do-, fo-, so- and words starting with bha-, bhla-, bhra-, dha-, gha-, ghla-, ghra-, mha-, e.g., do-ghlanta; fo-bhaile; so-mharaithe;
5. in specific titles and their initial letters, e.g., an Ard-Chúirt; an tArd-Aighne; an Príomh-Aire; an Príomh-Bhreitheamh;
6. after an- (emphatic prefix) and after dea-, e.g., an-aimsir; dea-bhéas. Note that the second word is not lenited in a compound word after an- when d, t or s follows it, e.g., an-duine is ea é; an-drochaimsir (see 10.2.12).

Note

1. Two hyphens are placed in a compound word when it is necessary for the sake of clarity, e.g., an-dea-aimsir; an-droch-chaint; iar-nua-aimseartha; an Leas-Phríomh-Aire.
2. The placement of a hyphen is not needed in an administrative term with more than one prefix if the meaning of the term is clear without it, e.g., comhfhochoiste; roghfhochoiste.
3. Note if iar is coming before a title starting with a capital letter, the placement of a hyphen is not necessary between iar and the title, e.g., an t‑iarArd-Reachtaire Cuntas agus Ciste.

This declension includes most of the masculine nouns ending in a broad consonant in the nominative singular. The nouns in the first declension are all masculine.

1. In the genitive singular, the last consonant is palatalized, e.g., bord, boird; nuachtán, nuachtáin.
2. The changes under 2.1.4 apply with the palatalization, but -ia- is not changed to -éi- in these nouns: Brian, Briain; cliant, cliaint; fiar, fiair; giar, giair; rian, riain; srian, sriain; and trian, triain.
3. mac is changed to mic in the genitive singular and in the genitive plural.
4. In the genitive singular, -ea- is changed to -i-, e.g., breac, bric; cuireadh, cuiridh; leiceann, leicinn; other than with certain monosyllabic nouns, e.g., each, eich.

1. The form is usually the same in the vocative singular as in the genitive singular, e.g., a Chorcaígh, a mhic, a Sheáin.

2. However, it is not customary to inflect in the vocative singular:

   1. on collective names, e.g., a chomhthionól; a phobal;
   2. on nouns used with a metaphorical meaning or as proper names, e.g., a cheann cipín; a chumann; a ghrá geal; a rós geal; a rún; a stór;
   3. on nouns that have a definite genitive subject, e.g., a Chléireach na Dála; a fhear an tí; a scáthán an chirt; a shólás na ndobrónach;
   4. on multi-word official titles, e.g., a Cheann Comhairle; a Oifigeach Ealaíon; a Cheann Scoile.

There are both weak plurals and strong plurals in this declension. The nouns that palatalize the final consonant are weak plurals, e.g., amhrán; amhráin; or have -a with them without other changes, e.g., nod; noda; úll; úlla; in the genitive plural. All the other nouns are strong plurals.

Note that the First Declension pattern appears in the genitive singular column in the following tables, namely, that the final consonant is palatalized and -(e)ach is changed to -(a)igh.

1. Strong Plurals

   Table 2FStrong Plurals in the First Declension — Examples

   Strong Plural Classes	Singular		Plural
   	Nominative	Genitive	Every Case
   Nouns ending in -ta, -tha in the singular Most of the monosyllabic nouns in which there is a long vowel (or diphthong) and end with -l, -n (but not -ll, -nn) in the nominative singular. -tha is put in the plural with occasional nouns ending with -r (but not -rr) in the nominative singular.	braon	braoin	braonta
   	fál	fáil	fálta
   	glór	glóir	glórtha
   	líon	lín	líonta
   	pór	póir	pórtha
   	tuar	tuair	tuartha
   Nouns ending with -aí, -i in the plural Certain monosyllabic nouns ending with -ch, and some in -dh, in the nominative singular, as with some other nouns.	árthach	árthaigh	árthaí
   	cladach	cladaigh	cladaí (gen. pl. cladach)
   	cúram	cúraim	cúraimí
   	daichead	daichid	daichidí
   	margadh	margaidh	margaí
   Nouns ending with -taí, -thaí in the plural	aonach	aonaigh	aontaí
   	dearcadh	dearcaidh	dearcthaí
   	toradh	toraidh	torthaí
   Nouns ending with -anna in the plural	cás	cáis	cásanna
   	praghas	praghais	praghsanna
   	saghas	saghais	saghsanna
   Nouns ending with -e in the plural and syncopated	bóthar	bóthair	bóithre
   	doras	dorais	doirse
   	uasal	uasail	uaisle
   Nouns ending with -(e)acha in the plural	cineál	cineáil	cineálacha
   	coinníoll	coinníll	coinníollacha
   	tobar	tobair	toibreacha
   Nouns ending with -te in the plural	claíomh	claímh	claimhte
   	muileann	muilinn	muilte
   	smaoineamh	smaoinimh	smaointe
   Miscellaneous nouns	breitheamh	breithimh	breithiúna
   	briathar	briathair	briathra
   	gníomh	gnímh	gníomhartha
   	scaitheamh	scaithimh	scaití

2. Weak Plurals

   Table 2GWeak Plurals in the First Declension — Examples

   Weak Plural Classes	Singular		Plural
   	Nominative	Genitive	Nominative	Genitive
   Nouns that get narrowed in the nominative plural	amhrán	amhráin	amhráin	amhrán
   	beithíoch	beithígh	beithígh	beithíoch
   	foirgneamh	foirgnimh	foirgnimh	foirgneamh
   	iasc	éisc	éisc	iasc
   Nouns ending in -a in the nominative plural	bruach	bruaigh	bruacha	bruach
   	ceap	cip	ceapa	ceap
   	giall	géill	gialla	giall
   	úll	úill	úlla	úll

3. The Vocative Plural

   The vocative plural form is the same as the nominative plural except in the weak plurals. Normally, -a is added to the form inf the nominative singular of those nouns to form the vocative plural, e.g., Corcaíoch, a Chorcaíocha; fear, a fheara; Gael, a Ghaela.

Nouns in this declension end with a consonant, broad or slender, in the nominative singular. They are all feminine other than im and sliabh.

1. An -e is put with the nominative singular and if it ends with a broad consonant, it is palatalized, e.g., bróg, bróige; coill, coille; earr, eirre; except with polysyllabic nouns ending with -(e)ach.
2. When polysyllabic nouns end with -(e)ach, -(a)í is made from -(e)ach, e.g., scornach, scornaí; cailleach, caillí.
3. The palatalization changes mentioned in 2.1.4 apply to the nouns as follows:
   1. -ea- to -ei-, e.g., beach, beiche (-ea- is changed to -i- in a monosyllabic noun, e.g., beann, binne; cearc, circe; and in the unaccented syllable of the polysyllabic noun, e.g., bruinneall, bruinnille; ficheall, fichille); and
   2. -ia- to -i- in the word scian, scine.

There are two forms of the dative singular when nouns end with a broad consonant:

1. one form is the same as the nominative singular;
2. a distinct old form used only in well-established expressions, e.g., cur i gcéill; cur dá chois; airgead ar láimh; bolg le gréin; imithe le gealaigh; cur de láimh; faoi bhois an chait; bíonn a chroí ar a bhois i gcónaí aige; ar éill; etc.

There are both weak plurals and strong plurals in this declension.

Note that the pattern of the Second Declension is seen in the genitive singular column in the following tables. That is, the genitive singular ends with -e and the final consonant is palatalized if it is a broad consonant, and for polysyllabic nouns ending in -each, -each is changed to -(a)í.

1. Strong Plurals

   Table 2HStrong Plurals in the Second Declension — Examples

   Strong Plural Classes	Singular		Plural
   	Nominative	Genitive	Every Case
   Nouns ending in -a in the plural and syncopated, whose vowels are broadened or exchanged	dabhach	daibhche	dabhcha
   	roinn	roinne	ranna
   	scian	scine	sceana
   Nouns ending in -(e)anna in the plural	áit	áite	áiteanna
   	blaosc	blaoisce	blaoscanna
   	im	ime	imeanna
   Nouns ending in -í in the plural Polysyllabic nouns ending in a slender consonant in the nominative singular.	abairt	abairte	abairtí
   	cáipéis	cáipéise	cáipéisí
   	earráid	earráide	earráidí
   Nouns ending in -(e)acha in the plural Monosyllabic nouns, and polysyllabic nouns ending in a slender consonant in the nominative singular (other than iníon which ends on a broad consonant).	bainis	bainise	bainiseacha
   	iall	éille	iallacha
   	iníon	iníne	iníonacha
   	maidin	maidine	maidineacha
   Nouns ending in -ta in the plural Some monosyllabic nouns ending in a broad -l or -n in the nominative singular.	buíon	buíne	buíonta
   	grian	gréine	grianta
   	steall	steille	steallta
   Nouns ending in -te in the plural The occasional noun ending in a slender -l or -n in the nominative singular.	aill	aille	aillte
   	bléin	bléine	bléinte
   	linn	linne	linnte
   Nouns ending in -e in the plural and that are syncopated	caingean	caingne	caingne
   	coinneal	coinnle	coinnle
   	foireann	foirne	foirne
   	maighean	maighne	maighne
   Miscellaneous nouns	culaith	culaithe	cultacha
   	gualainn	gualainne	guaillí
   	sliabh	sléibhe	sléibhte
   	uair	uaire	uaireanta

2. Weak Plurals

   Table 2IWeak Plurals in the Second Declension — Examples

   Weak Plural Classes	Singular		Plural
   	Nominative	Genitive	Nominative	Genitive
   Monosyllabic and polysyllabic nouns ending in a broad consonant in the nominative singular and have a -a added in the nominative plural and no other changes	amharclann	amharclainne	amharclanna	amharclann
   	beach	beiche	beacha	beach
   	dallóg	dallóige	dallóga	dallóg
   	gealach	gealaí	gealacha	gealach
   	girseach	girsí	girseacha	girseach
   	maighdean	maighdine	maighdeana	maighdean
   Nouns that are broadened and end in -a in the nominative plural	cill	cille	cealla	ceall
   	deoir	deoire	deora	deor
   	ealaín	ealaíne	ealaíona	ealaíon
   	rinn	rinne	reanna	reann
   The occasional noun ending in a slender consonant in the nominative singular and ending in -e in the nominative plural	ainimh	ainimhe	ainimhe	aineamh
   	dúil	dúile	dúile	dúl
   	glúin	glúine	glúine	glún
   	súil	súile	súile	sú

1. This declension has the polysyllabic nouns ending in -áil, -aíl, -cht, -éir, -eoir, -irt, -óir, -úil, -úint, -úir (other than country names that are in the second declension, e.g., an Ailgéir, an Bhrasaíl, an Iodáil).
2. This declension also has some nouns ending in a consonant, broad or slender, in the nominative singular. For these nouns, the genitive singular ends with -a and the final consonant is broadened if necessary, e.g., buachaill, buachalla; gleann, gleanna (see 2.1.5).

1. As with in (b) above, the genitive singular ends with -a.
2. It is customary to change -io- to -ea- in the genitive singular for monosyllabic nouns, e.g., crios, creasa; lios, leasa; but not cion (meaning coir, (EN: crime)), ciona.
3. The -t is dropped in the genitive singular from nouns ending in -int, e.g., oiliúint, oiliúna (with these exceptions cogaint, coganta; cosaint, cosanta; seachaint, seachanta). The -th- is turned to -t when nouns end in -irt, e.g., imirt, imeartha.

There are both weak plurals and strong plurals in this declension.

Note that the pattern of the Third Declension is seen in the genitive singular column in the following table. That is, the genitive singular ends with -a and the last consonant is broadened if it is a slender consonant.

1. Strong Plurals

   Table 2JStrong Plurals in the Third Declension — Examples

   Strong Plural Classes	Singular		Plural
   	Nominative	Genitive	Every Case
   Nouns ending in -(a)í in the plural Polysyllabic nouns (masculine other than a few, e.g., altóir, seanmóir) ending in -éir, -eoir, -óir, -úir, and polysyllabic nouns (feminine other than few, e.g., bunreacht, comhlacht, complacht, gnólacht) ending in -cht, -irt, -úint in the nominative singular.	athnuachan	athnuachana	athnuachaintí
   	bagairt	bagartha	bagairtí
   	báicéir	báicéara	báicéirí
   	beannacht	beannachta	beannachtaí
   	dlíodóir	dlíodóra	dlíodóirí
   	dochtúir	dochtúra	dochtúirí
   	eisiúint	eisiúna	eisiúintí
   	múinteoir	múinteora	múinteoirí
   Nouns ending in -(e)anna in the plural Polysyllabic masculine nouns (other than some that are feminine, e.g., cuid, dleacht, troid, uaim).	droim	droma	dromanna
   	rang	ranga	ranganna
   	troid	troda	troideanna
   Nouns ending in -a in the plural and syncopated, broadened or exchanged vowels	feadhain	feadhna	feadhna
   	gamhain	gamhna	gamhna
   	slios	sleasa	sleasa
   Nouns ending in -acha in the plural Polysyllabic feminine nouns ending in a slender -l, -n or -r (exceptions: anam, anama, anamacha; úim, úma, úmacha) in the nominative singular. Note that this is also how the genitive singular of a noun ending in -aíl is formed, e.g., feadaíl, feadaíola; sceamhaíl, sceamhaíola.	admháil	admhála	admhálacha
   	barúil	barúla	barúlacha
   	fíniúin	fíniúna	fíniúnacha
   	onóir	onóra	onóracha
   Nouns ending in -ta in the plural Monosyllabic nouns ending in -l or -n that is broad (masculine) or slender (feminine) in the nominative singular.	cion (meaning coir)	ciona	cionta
   	feoil	feola	feolta
   	gleann	gleanna	gleannta
   Nouns ending in -te in the plural	cluain	cluana	cluainte
   	móin	móna	móinte
   	táin	tána	táinte
   Miscellaneous Nouns	anacair	anacra	anacraí
   	buachaill	buachalla	buachaillí
   	conradh	conartha	conarthaí
   	maitheas	maitheasa	maitheasaí
   	roth	rotha	rothaí

2. Weak Plurals

   Table 2KWeak Plurals in the Third Declension — Examples

   Weak Plural Classes	Singular		Plural
   	Nominative	Genitive	Nominative	Genitive
   Miscellaneous nouns	béas	béasa	béasa	béas
   	dreas	dreasa	dreasa	dreas
   	mionn	mionna	mionnaí	mionn
   	tréad	tréada	tréada	tréad
   	treas	treasa	treasa	treas

1. This declension has the masculine nouns ending in -ín, diminutives ending in -ín, the majority of the nouns ending in a vowel, and a small number of other nouns.
2. Occupational nouns ending in -(a)í or -aire are also masculine, e.g., ceannaí, cócaire.
3. Abstract nouns ending in -e and formed from an adjective are feminine, e.g., airde, gile, saoirse.

1. Nouns of this declension do not undergo any change in the genitive singular.
2. The diminutive -ín normally is feminine if the original word is a common feminine word. There are exceptions, e.g., paidir (fem.), paidrín (masc.); toit (fem.), toitín (masc.). However, all diminutives are declined as masculine nouns in the genitive and vocative singular, e.g., an bheainín bheag, teach an bheainín bhig, a bheainín bhig.
3. There are some nouns in this Declension that do not have any plural, e.g., cruach (meaning miotal (EN: metal)), dóthain, gorta, lucht (meaning daoine (EN: people)), oiread, tobac.

The vast majority of the nouns in this declension have strong plurals.

Note that the Fourth Declension’s pattern is shown in the singular column in the table below. That is, the form of the genitive singular is the same as the form of the nominative plural.

1. Strong Plurals

   Table 2LStrong Plurals in the Fourth Declension — Examples

   Strong Plural Classes	Singular
   	Every Case	Every Case
   Nouns ending in -(a)í in the plural Nouns ending in -a, -e, -ín in the singular.	altra	altraí
   	báidín	báidíní
   	fáinne	fáinní
   Nouns ending in -te in the plural Occasional nouns ending in -le, -ne in the singular.	baile	bailte
   	sloinne	sloinnte
   	tine	tinte
   Nouns ending in -(i)the in the plural Nouns ending in -(a)í, -aoi, -é in the singular (-í- is not shortened in the monosyllabic nouns, other than ní, nithe).	ainmhí	ainmhithe
   	draoi	draoithe
   	giúiré	giúiréithe
   	rí	ríthe
   Nouns ending in -nna in the plural Nouns ending in -á, -ao, -eá, -eo, -ia, -ó, -ogha, -ú, -ua in the singular.	bogha	boghanna
   	ceo	ceonna
   	cnó	cnónna
   	cú	cúnna
   	grua	gruanna
   	íomhá	íomhánna
   	lao	laonna
   	meá	meánna
   	nia	nianna
   Some nouns ending in a consonant in the singular and have -(e)anna added in the plural and no other changes	bus	busanna
   	seic	seiceanna
   	téacs	téacsanna
   Occasional nouns ending in -ite in the plural	comhrá	comhráite
   	cró	cróite
   	crú	crúite
   	rá	ráite
   	slua	sluaite
   Miscellaneous nouns	achainí	achainíocha
   	airí	airíonna
   	aithne	aitheanta
   	aturnae	aturnaetha
   	bó	ba (gen. pl. bó)
   	cine	ciníocha
   	claí	claíocha
   	duine	daoine
   	gabha	gaibhne
   	gnó	gnóthaí
   	oíche	oícheanta
   	slí	slite
   	teanga	teangacha

1. The majority of the nouns in this declension are feminine.
2. This declension also has some nouns ending in slender consonants or a vowel in the nominative singular and on a broad consonant (-ch, -d, -(n)n, -r) in the genitive singular.

The vast majority of nouns in this declension have strong plurals.

Note that the pattern of the Fifth Declension is shown in the genitive singular column of the following table. That is, the genitive singular ends with broad consonants -ch, -d, -(n)n, -r (other than rare exceptions, e.g., Nollaig, Nollag).

1. Strong Plurals

   Table 2MStrong Plurals in the Fifth Declension — Examples

   Strong Plural Classes	Singular		Plural
   	Nominative	Genitive	Every Case
   Nouns ending in -(e)acha in the plural Feminine nouns ending in -il, -in, -ir in the nominative singular (exceptions: siúr, siúrach). In the genitive singular, the final consonant of a monosyllabic noun is broadened, and other nouns do not undergo syncopation, and an -ach is added (exceptions: cathaoir, cathaoireach). Polysyllabic nouns are syncopated if they have a short vowel in the final syllable and -(e)ach is added.	cathair	cathrach	cathracha
   	draein	draenach	draenacha
   	litir	litreach	litreach
   	rial	rialach	rialacha
   	traein	traenach	traenacha
   	treoir	treorach	treoracha
   	triail	trialach	trialacha
   	uimhir	uimhreach	uimhreacha
   The occasional nouns that ends in -inn, -ir in the nominative singular, broadened in the genitive singular and ending in -(e)acha in the plural. (Exceptions: bráthair, bráthar, bráithre.)	abhainn	abhann	aibhneacha
   	máthair	máthar	máithreacha
   	teorainn	teorann	teorainneacha
   Nouns ending in -na, -ne in the plural Feminine nouns ending in a vowel in the nominative singular and in -n in the genitive singular (exceptions: díle, díleann, dílí; lacha, lachan, lachain (gen. sg. lachan)).	ceathrú	ceathrún	ceathrúna
   	comharsa	comharsan	comharsana (gen. pl. comharsana)
   	ionga	iongan	ingne
   	leite	leitean	—
   	monarcha	monarchan	monarchana
   	pearsa	pearsan	pearsana (gen. pl. pearsan)
   Nouns ending in -idí in the plural The occasional masculine noun ending in -d in the genitive singular. Note that daichead (daichid, daichidí) belongs to the first declension.	fiche (dat. sg. fichid)	fichead	fichidí
   	tríocha	tríochad	tríochaidí
   	ceathracha	ceathrachad	ceathrachaidí
   	caoga	caogad	caogaidí
   	seasca	seascad	seascaidí
   	seachtó	seachtód	seachtóidí
   	ochtó	ochtód	ochtóidí
   	nócha	nóchad	nóchaidí
   Miscellaneous nouns	bráid	brád	bráide
   	cara	carad	cairde
   	caora	caorach	caoirigh (gen. pl. caorach)
   	Éire (dat. sg. Éirinn)	Éireann	—
   	namhaid	namhad	naimhde
   	Nollaig	Nollag	Nollaigí